214 research outputs found

    Analysis of Energy Consumption Performance towards Optimal Radioplanning of Wireless Sensor Networks in Heterogeneous Indoor Environments

    Get PDF
    In this paper the impact of complex indoor environment in the deployment and energy consumption of a wireless sensor network infrastructure is analyzed. The variable nature of the radio channel is analyzed by means of deterministic in-house 3D ray launching simulation of an indoor scenario, in which wireless sensors, based on an in-house CyFi implementation, typically used for environmental monitoring, are located. Received signal power and current consumption measurement results of the in-house designed wireless motes have been obtained, stating that adequate consideration of the network topology and morphology lead to optimal performance and power consumption reduction. The use of radioplanning techniques therefore aid in the deployment of more energy efficient elements, optimizing the overall performance of the variety of deployed wireless systems within the indoor scenario

    Relationship Between Mitochondrial Structure and Bioenergetics in Pseudoxanthoma elasticum Dermal Fibroblasts

    Get PDF
    Pseudoxanthoma elasticum (PXE) is a genetic disease considered as a paradigm of ectopic mineralization disorders, being characterized by multisystem clinical manifestations due to progressive calcification of skin, eyes, and the cardiovascular system, resembling an age-related phenotype. Although fibroblasts do not express the pathogenic ABCC6 gene, nevertheless these cells are still under investigation because they regulate connective tissue homeostasis, generating the “arena” where cells and extracellular matrix components can promote pathologic calcification and where activation of pro-osteogenic factors can be associated to pathways involving mitochondrial metabolism. The aim of the present study was to integrate structural and bioenergenetic features to deeply investigate mitochondria from control and from PXE fibroblasts cultured in standard conditions and to explore the role of mitochondria in the development of the PXE fibroblasts’ pathologic phenotype. Proteomic, biochemical, and morphological data provide new evidence that in basal culture conditions (1) the protein profile of PXE mitochondria reveals a number of differentially expressed proteins, suggesting changes in redox balance, oxidative phosphorylation, and calcium homeostasis in addition to modified structure and organization, (2) measure of oxygen consumption indicates that the PXE mitochondria have a low ability to cope with a sudden increased need for ATP via oxidative phosphorylation, (3) mitochondrial membranes are highly polarized in PXE fibroblasts, and this condition contributes to increased reactive oxygen species levels, (4) ultrastructural alterations in PXE mitochondria are associated with functional changes, and (5) PXE fibroblasts exhibit a more abundant, branched, and interconnected mitochondrial network compared to control cells, indicating that fusion prevail over fission events. In summary, the present study demonstrates that mitochondria are modified in PXE fibroblasts. Since mitochondria are key players in the development of the aging process, fibroblasts cultured from aged individuals or aged in vitro are more prone to calcify, and in PXE, calcified tissues remind features of premature aging syndromes; it can be hypothesized that mitochondria represent a common link contributing to the development of ectopic calcification in aging and in diseases. Therefore, ameliorating mitochondrial functions and cell metabolism could open new strategies to positively regulate a number of signaling pathways associated to pathologic calcification

    Threading holder based on axial metal cylinder pins to reduce tap risk during reversion instant

    Get PDF
    Internal thread profiles are used widely in manufacturing processes with the aim of assembling/disassembling different components during maintenance activities from the aeronautics sector until common industrial parts. The threading process is one of the last operations carried out to obtain those components, and consequently, it is an operation of high added value. Threading is a complex operation that must carefully synchronize the rotation with the feed movements to avoid tool breakage during the instant of tapping reversion stage. In order to avoid this risk, several toolholders were developed present in the literature but deficiencies in terms of stability and productivity. Therefore, in this work, a new toolholder is proposed in which the common springs used to mitigate the lack of perfect synchronization between rotation and feed movements are replaced by elastic metal pins achieving a torsional compliance toolholder. The results show that the use of the proposed toolholder implies not only a productivity increase but also a surface integrity improvement as well as a stress reduction that the cutting tap is subjected and thus, achieving a substantial improvement in the current tapping processes. In particular, the use of the proposed toolholder implied a 75% reduction of the maximum stress achieved in the reversal instant, improving 20% tool life with an increase of 30% cutting speed. Therefore, the use of the proposed toolholder implies a substantial improvement in the current tapping processes

    COVID-19 and Sick Leave: An Analysis of the Ibermutua Cohort of Over 1,651,305 Spanish Workers in the First Trimester of 2020

    Get PDF
    Objectives: The worldwide SARS-COV2 pandemic has impacted the health of workers and companies. The aim is to quantify it according to sick leave. Methods: Using ICD-9 codes, we analyzed Ibermutua records of all sick leaves during the first trimester of 2020, compared to during the same months of 2017, 2018, and 2019. We stratified the analysis by causes, patient sex, activity sectors, and regional data. All sick leaves were adjusted by the number of Ibermutua-affiliated persons in each period. Results: In March 2020, there was an unprecedented (116%) increase in total sick leaves, mainly due to infectious and respiratory diseases. Men and women were equally affected. All activity sectors were impacted, with the highest increase (457%) observed among health-related workers, especially due to contagious disease. The incidences of sick leaves were heterogeneous among different regions. Cost-analysis of sick leaves during the first trimester of 2020 compared with in previous years showed 40.3% increment (mean 2,813 vs. 2,005 euro per 100 affiliated workers). Conclusions: The SARS-COV2 pandemic is having a huge impact on workers' health, as shown by data regarding sick leaves in March 2020. This is associated with greater economic burden for companies, both due to the cost associated with sick leaves and the losses in productivity due to confinement

    Astronomical Spectroscopy

    Full text link
    Spectroscopy is one of the most important tools that an astronomer has for studying the universe. This chapter begins by discussing the basics, including the different types of optical spectrographs, with extension to the ultraviolet and the near-infrared. Emphasis is given to the fundamentals of how spectrographs are used, and the trade-offs involved in designing an observational experiment. It then covers observing and reduction techniques, noting that some of the standard practices of flat-fielding often actually degrade the quality of the data rather than improve it. Although the focus is on point sources, spatially resolved spectroscopy of extended sources is also briefly discussed. Discussion of differential extinction, the impact of crowding, multi-object techniques, optimal extractions, flat-fielding considerations, and determining radial velocities and velocity dispersions provide the spectroscopist with the fundamentals needed to obtain the best data. Finally the chapter combines the previous material by providing some examples of real-life observing experiences with several typical instruments.Comment: An abridged version of a chapter to appear in Planets, Stars and Stellar Systems, to be published in 2011 by Springer. Slightly revise

    Low-resolution spectroscopy and spectral energy distributions of selected sources towards sigma Orionis

    Get PDF
    Aims: We investigated in detail nine sources in the direction of the young sigma Orionis cluster, which is considered a unique site for studying stellar and substellar formation. The nine sources were selected because of some peculiar properties, such as extremely red infrared colours or too strong Halpha emission for their blue optical colours. Methods: We took high-quality, low-resolution spectroscopy (R ~ 500) of the nine targets with ALFOSC at the Nordic Optical Telescope. We also re-analyzed [24]-band photometry from MIPS/Spitzer and compiled the best photometry available at the ViJHKs passbands and the four IRAC/Spitzer channels for constructing accurate spectral energy distributions covering from 0.55 to 24 mum. Results: The nine targets were classified into: one Herbig Ae/Be star with a scatterer edge-on disc, two G-type stars, one X-ray flaring, early-M, young star with chromospheric Halpha emission, one very low-mass, accreting, young spectroscopic binary, two young objects at the brown dwarf boundary with the characteristics of classical T Tauri stars, and two emission-line galaxies, one undergoing star formation, and another one whose spectral energy distribution is dominated by an active galactic nucleus. Besides, we discover three infrared sources associated to overdensities in a cold cloud in the cluster centre. Conclusions: Low-resolution spectroscopy and spectral energy distributions are a vital tool for measuring the physical properties and the evolution of young stars and candidates in the sigma Orionis cluster.Comment: Accepted for publication in A&

    Effectiveness of primary health care in the diagnosis and treatment of arterial hypertension

    Get PDF
    La hipertensiĂłn arterial (HTA) es un importante problema de salud pĂșblica, por su elevada morbimortalidad cardiovascular y sus costes econĂłmicos y sociales. Fundamento. Identificar la prevalencia de HTA detectada en atenciĂłn primaria y su grado de control; conocer los tipos de tratamientos utilizados y factores asociados a su control. Pacientes y mĂ©todos. Estudio transversal comparativo de dos años en el Centro de Salud de Villava. Se analizan los datos de la historia clĂ­nica informatizada en los años 2003 y 2006. Se estudian las variables: edad, gĂ©nero, pensiĂłn arterial sistĂłlica y diastĂłlica, colesterol total, HDL, LDL, triglicĂ©ridos, tabaquismo, Ă­ndice de masa corporal en ambos años. Tratamiento hipotensor en el año 2006. Mediante regresiĂłn logĂ­stica se identifican las variables del año 2006 asociadas a buen control. Resultados. Prevalencia detectada de HTA en ≄18 años: 2003: 11,6% (IC:10,9-12,3); 2006: 16,6% (IC:15,8-17,4) (p<0,001). En hipertensos con registro de presiĂłn arterial estaban controlados (PA:<140/90) en 2003: 45,1% (IC: 41,0- 48,0) y en 2006: 40,4% (IC: 37,7-43,2) (p<0,05). Variables asociadas a buen control: ser varĂłn [OR 1,60 (IC: 1,26-2,03)] tratamiento con ARA II [OR 2,16 (IC: 1,50-3,09)] y ser diabĂ©tico [OR 1,50 (IC: 1,10-2,03]. Se asocian a mal control: presentar enfermedad vascular cerebral, vasculopatĂ­a perifĂ©rica y el tratamiento con IECA. Conclusiones. La prevalencia de HTA detectada es baja. El nivel de control es superior para la PAD que para la PAS. El tratamiento con ARA II, ser varĂłn o ser diabĂ©tico se asocia a mejor control. La vasculopatĂ­a perifĂ©rica, la cardiopatĂ­a isquĂ©mica, la enfermedad vascular cerebral, el tratamiento con IECA y edad se asocian a peor control.Arterial hypertension (AHT) is a significant public health problem due to its high cardiovascular morbidity and mortality and its economic and social costs. Background. To identify the prevalence of AHT detected in primary care and its degree of control; to determine the types of treatment used and factors associated with its control. Patients and methods. Transversal comparative study of two years in the Villava Health Centre. The computerised clinical history data for the years 2003 and 2006 was analysed, The following variables were Studied: age, gender, systolic and diastolic arterial pressure, total cholesterol, HDL, LDL, triglycerides, tobacco use, body mass index in both years. Hypotensor treatment in the year 2006. The variables fort lie year 2006 associated with good control were identified through logistic regression. Results. AHT prevalence detected in >= 18 year olds: 2003: 11.6% (CI: 10.9-12.3); 2006: 16.6% (CI: 15.8-17.4) (p < 0.001). Control of hypertense persons with a register of arterial tension (AP: <140/90) in 2003; 45.1% (CI: 41.0-48.0) and in 2006: 40.4% (CI: 37.7-43.2) (p < 0.05). Variables associated with good control: being male [OR 1.60 (IC: 1.26-2.03)] treatment with ARA II [OR 2.16 (CI: 1.50-3.09)] and being diabetic [OR 1.50 (CI: 1.10-2.03]. Associated with poor control: presenting cerebral vascular disease, peripheral vasculopathy and treatment with ACE inhibitors. Conclusions. A low prevalence of AHT was detected. The level of control was higher for the DAP than for the SAP. Treatment with AURA, being male and being diabetic were associated with a better control. Peripheral vasculopathy, ichaemic cardiopathy, cerebral vascular disease, ACE inhibitors use and age were associated with a poorer control

    Prevalence of vertebral fractures and their prognostic significance in the survival in patients with chronic kidney disease stages 3-5 not on dialysis

    Get PDF
    The prevalence of vertebral fractures (VF) and their association with clinical risk factors and outcomes are poorly documented in chronic kidney disease (CKD) cohorts. The aim of the study was to evaluate the prevalence of VF in patients with non-dialysis dependent CKD (NDD-CKD), their value in predicting mortality and its correlation with parameters of bone mineral metabolism and vascular calciïŹcation. 612 NDD 3-5 stage CKD patients participating in the OSERCE-2 study, a prospective, multicenter, cohort study, were prospectively evaluated and categorized into two groups according to presence or absence of VF at enrollment. VF were assessed with lateral radiographs and Genant semi-quantitative method was applied. Three radiologists specialized in musculoskeletal radiology performed consensual reading of individual images obtained using a Raim DICOM Viewer and a Canon EOS 350 camera to measure with Java Image software in those who had traditional acetate X-ray. Factors related to VF were assessed by logistic regression analysis. Association between VF and death over a 3-year follow-up was assessed by Kaplan-Meier survival curves and Cox-proportional hazard models. VF were detected in 110patients(18%). Serumphosphatelevels(OR0.719,95%CI0.532to0.972,p = 0.032),ankle-brachial index 3 and serum phosphate, the presence of VF (HR 1.983, 95% CI 1.009-3.898, p = 0.047) were an independent predictor of all-cause mortality. In our study 18% of patients with NDD-CKD have VF. Factors associated with VF were age, low serum phosphate levels and peripheral vascular disease. The presence of VF was an independent risk factor for mortality in stages 3-5 NDD-CKD patients. Clinical trials are needed to conïŹrm whether this relationship is causal and reversible with treatment for osteoporosis

    The nature of G52.381-0.849 and G56.240-0.345: young stellar objects associated with extended mid-infrared emission?

    Full text link
    We report the results of visual spectroscopy, mid-infrared (MIR) mapping and photometry, and near-infrared photometry of two candidate symbiotic stars (IPHAS J193108.67+164950.5 and IPHAS J193709.65+202655.7) associated with extended MIR emission. Our analysis of the continua of these sources shows that they are likely to represent Class I-II young stellar objects (YSOs) in which most of the IR emission arises from circumstellar discs, and for which the physical characteristics (stellar temperatures, radii, masses and luminosities) are similar. The extended emission is characterized by a substantial increase in fluxes and dimensions to longer MIR wavelengths. This is likely to arise as a result of emission by polycyclic aromatic hydrocarbons within extended photodissociation regimes, centred upon more compact ionized regions responsible for much of the shorter wave emission. Such dual emission structures are characteristic of those observed in many compact HII regions. Finally, we note that the clouds have asymmetrical structures and wind-swept morphologies, conceivably indicative of shock interaction with external winds. Where this is the case, then it is possible that the YSOs are located in regions of triggered star formation.Comment: 10 pages, 7 figures, Accepted for publication in MNRAS. 25 pages in arXi
    • 

    corecore